The existence of developmental plasticity in the neuronal circuitry of the vertebrates is well established. Recently developmental plasticity in many respects not unlike that found in the vertebrates has been demonstrated in an invertebrate nervous system (e.g. Acheta domesticus). It has been demonstrated physiologically that the input- output relations of a group of uniquely identifiable first order interneurons found in this species are modified by sensory deprivation. It is proposed here that the developmental control of dendritic geometry of these identifiable neurons be investigated using single cell recording and dye injection techniques. Sensory deprivation experiments will be used to modify the environment in which the neuron matures. The experiments, consisting of three different deprivation regimes, are designed to delineate the normal development of the geometry of identifiable neurons, the role afferents play in the normal expression of that form, and the role neural activity in the afferents plays in the expression of the neuron's form.